This invention relates to a gasket and more particularly to an intake manifold gasket having a rubber compression limiter and a rubber sealing member disposed thereon.
Gaskets are typically placed between a pair of mated mechanical components having a quantity of fluid contained between them. The gasket, so placed, acts to seal the contained fluid so as to prevent the fluid from escaping into the surrounding area.
These gaskets usually contain a plastic core upon which rubber or fiber type material is placed. The core and deposited material define the body of the gasket. A number of openings are placed through the gasket body, each opening allowing a single shank of a conventional fastener, such as a stud bolt, to pass therethrough thereby securing the gasket between the mated components. A raised rubber sealing member is also deposited upon the gasket body and cooperates with the body to provide the aforementioned sealing action. Such sealing members may be placed upon both sides of the gasket body.
These prior gaskets have also included compression limiters, placed upon the gasket body, which have limited the amount by which the raised rubber sealing members may be compressed. Such compression is known to result from many sources including the compressing action of the attachment bolt head. These limiters have proven to be an important part of the gasket design since overcompression may result in structural damage to the sealing member and may result in a concominant loss of sealing ability.
These previous limiters were typically made of metal and were ordinarily placed upon and attached to the body of the gasket. In some previous designs, the metal limiters were replaced with a groove placed upon the plastic core and the sealing member was normally placed within the groove. The depth of the groove compared to the height of the rubber sealing member determined the maximum compression of the member.
Two separate molding steps are required to manufacture these prior gaskets. One molding step was needed to mold the plastic core and the other to mold the sealing member thereon. Additionally, the manufacture of these gaskets usually required the additional step of securing the metal limiters to the core or the creation of the limiter grooves thereon. If sealing members were required on both sides of the gasket, holes were usually placed through the core to facilitate this two-sided molding of the sealing members upon the body.
While these prior gaskets have proven to provide effective sealing action they have many drawbacks. That is, the manufacturing costs associated with these gaskets is relatively high due to the two required molding steps, the separate attachment of the metal limiters, and the placement of the holes through the core. Additionally, these prior gaskets have great variations in the height of the compression limiter relative to the height of the sealing member. This variation not only causes great differences in compression tolerances across a wide range of manufactured gaskets but also causes differences in compression tolerances within a single gasket wherein these differences depend upon the point that the sealing member is being compressed.
It is therefore an object of this invention to provide a gasket having a compression limiter of the same material as the sealing member and having a relatively low height and large compression area compared to the sealing member so as to prevent the overcompression of the sealing member.
It is another object of this invention to provide a gasket having a compression limiter and sealing member disposed thereon wherein, the height of the sealing member is greater than the height of the compression limiter so that the seal member is compressed to achieve the desired gasket action before the limiter is engaged to prevent undue compression of the seal.
It is yet another object of this invention to provide a gasket having a perforated steel body and having a relatively low manufacturing cost.
These and other aspects, features, advantages, and objects of this invention will be more readily understood upon reviewing carefully the following detailed description taken in conjunction with the accompanying drawings and appended claims.